Service Oriented Architecture (SOA) is changing how enterprise software is being designed and deployed. Part of the success of SOA is in the technology and is due to the convergence of web services standards creating a common interoperable set of technologies to build SOAs on. The other part of the success of SOA arises from its superior economic model for enterprises. SOA is evolving to the point where new applications will not be deployed as monolithic instances but will become a collection of services woven together in a loosely coupled framework. Applications are becoming virtualized and being made available on-demand this will break the current technological and economic bottleneck caused by the traditional enterprise software model. This problem does not reside with enterprise IT organizations but rather with the enterprise software model as a whole. In most cases though corporate IT is made the scapegoat for the problems with the enterprise software model. Until now there has not been an alternative to the traditional model of deploying silos of functionality now IT organizations have a choice and a way out of the current web of complexity.

The service based model of software is here and forward looking enterprises are rapidly adopting it as a means to streamline operations, reduce costs and provide significant differentiation in the marketplace. Successful companies are investing in services that differentiate the company, and outsource commodity services to organizations that deliver them more reliably, and more cost efficiently. Who today would invest in building an overnight parcel delivery service? Likewise who wants to invest millions of dollars in the design and implementation resources in a CRM system when you can get a service from one of several vendors for a fixed monthly fee that scales dynamically with the growth of your organization? This approach is going to solve several significant problems with today¬s enterprise software when it is broadly applied to the enterprise infrastructure. CRM is just a small example and the tip of the iceberg, when software as a service is used to build and deploy applications the economics are such that it becomes fiscally irresponsible not to consider this approach.

The current model of enterprise software is not aligned with the needs of corporate IT organizations its inefficient, cumbersome, and non responsive to the needs of companies. Measurements of return on investment (ROI) are, in many cases, optimistic at best. The percentage of failed projects by some accounts exceeds successful projects. While there have been and there will continue to be many successful deployments they are the result of careful planning and significant investment of a companies best and brightest IT personnel to ensure success. If the best and brightest are used to ensure successful rollouts - who is creating the business processes and applications that make the business successful? What percentage of the total IT effort is devoted to this?

Apart from the time to deployment and the inherent complexity of the current enterprise software offerings there is an even larger hidden problem. The actual value delivered when taken, as part of the total costs of development of the software is low. Enterprises pay a ¬portability tax¬ when buying software, the more complex the software the higher the ¬tax¬. This ¬tax¬ is the costs that go into making the enterprise software portable and compatible with the underlying operating systems, databases, application servers, mail servers, directory servers, etc. These costs contribute almost no value to the business objectives of the enterprise yet they can be a significant part of the cost model.

When these costs, of developing, deploying and supporting enterprise software are taken into account the amount devoted purely to ensuring that the software is designed to be run, deployed and supported on a variety of platforms is significant. Based on many years of experience I would estimate that anywhere between 30-70% of the total costs are devoted to cross platform issues. The upper range is for software that utilizes as many native (propriety) platform features as possible and the low end for software designed with a lowest common denominator approach. While this estimate may seem high, consider not just the actual coding efforts but all the other efforts. How much time in the requirements phase is spent discussing and evaluating which combination of platforms to support, which patch releases to support, and then how to design the software to support these features. Every time a new feature is added there is a design discussion on the cross platform impact. Add to this the test matrix and support infrastructure the costs continue to mount, but the value to the consumer of the software does not.

The impact of all this on the customer is that a significant part of the cost of enterprise software provides no significant business value to the enterprise. This has not been questioned, as there has been no viable alternative to this model. Now a viable alternative is being widely deployed through software as a service model.

Software as a service has become viable through three trends that have converged to create an opportunity for enterprises to drive significant costs out of their software purchases, provided faster response to market conditions, and reduce infrastructure. The three trends are SOA, broad availably high-speed connections, and web services. These trends enable software to be delivered as a service ¬ producers of services make services available on a SOA backbone, and then consumers can use the features inherent in the network to create applications by weaving together different services. Applications can now be created that are totally virtual and do not require hardware or software installation or deployment. Companies such as Grand Central are making the network smarter by deploying the necessary services for a SOA backbone. This is aligned with the objectives of corporate IT to build and deploy services that provide differentiation and leverage the services provided by others. The necessary framework to make this happen is not core to any one organization and as such should be shared infrastructure.

Deploying software as a service removes the significant problems with enterprise software as services only need to run on a single platform, therefore a larger percentage of the effort is in creating useful business applications not portable ones. Using shared infrastructure and other business services enables us to leverage the work of others in ways that have not been possible with the current model. The time to market or time to respond to market demands is shortened considerably as once again we are leveraging the services of others.

This will not happen overnight, nor am I suggesting that we rip out the current installed base of enterprise software. Far from it because the current installed based provides the core set of services required by the corporation and its partners today. The task is rather deciding which services are core to your business and investing in them and using services from others where appropriate. As in all technology revolutions the last generation usually remains a vital part of the infrastructure but not the only part. Software as a service is going to significantly reduce the need for enterprise software but not eliminate it. Software as a service is a more economically responsive model to the needs of IT and enables the corporation to focus more on the business process and the applications rather than the deployment of more enterprise software